I didn't make it a private invite because I figured the other two might want to invite friends and potentially some of our mutual friends might see it and want to come. I figured we'd invite our mutual friends anyway, but this way we wouldn't have to rehash all the details.

This sounds a bit confusing - you were expecting mutual friends to see the event and ask to come, but expected this particular Facebook friend to realize that the event wasn't intended for her? If you're posting something with the idea that people will see it and want to join in, then will apply to everyone who sees the event posting.

This, exactly. You were expecting other people might want to join, but then thought it was odd when this friend decided to join? I think this is odd on your part.

There's also the point of view that when an event is made public, it's something you're recruiting for pretty aggressively. The things that I've seen as a public event have been things like "my brother's band is playing" or "my friend's artwork is in a gallery" or "there's a charity run."

But not so much, "let's get together for a bit of conversation at a bar."

Also, people react to things online without reading everything; they scan.

I don't think it's rude per se, but it does seem a little odd to me. I was interested in what my fellow ehellions would think.

I added an event to fb last week. The invite was for an evening at a popular place to paint and drink wine. I had two friends that wanted to go and I thought it would be easier than texting back and forth. I didn't make it a private invite because I figured the other two might want to invite friends and potentially some of our mutual friends might see it and want to come. I figured we'd invite our mutual friends anyway, but this way we wouldn't have to rehash all the details.

On the invite were just 3 people: Jane, Tina, and me. Before Jane or Tina even responded a fb friend of mine who does not know either of the other two RSVP'd that she was coming.

Now, I understand that the fb event was public. I suppose she saw it in her newsfeed, thought "Cool, that's fun!" and RSVP'd. But I think it's weird that she RSVP'd to an event that she wasn't invited to and that she didn't know either of the other attendees. I mean, I did make it public purposely so that people that weren't formally invited could attend. I just didn't expect someone from outside of that circle to want to attend.

Does anyone else think this is odd? Or does this happen all the time?

PS. I did immediately change the invite to private, but I didn't kick her out. It's fine that she comes.

The bolded is where you made a mistake, you didn't specify which mutual friends. When you expose your invite to your entire friend's list, you are inviting them all and sundry. If you wanted it to be only for mutual friends, you should have restricted to that pool of mutual friends and added, "Please feel free to add whomever else you wish to attend this." (with whatever wording)

I agree with this. There's an option on FB events, even private ones, on who can invite guests. There's only the host, or friends can invite others as well, but it still shows up as a private event.

Honestly, if I saw a friend do a public event like that and I got a prompt on my FB feed (a You Might Be Interested In sort of thing) I probably wouldn't join (social anxiety, and even if I get a direct invite, I'm still not sure if they really want me there or not), but I know plenty of people who would.

In any case, you handled it well by changing the event to private and still letting the friend come, not kicking her out. I hope you all have/had a good time at it!

When I was still in school I had two separate people who I didn't know, on two separate occasions, RSVP to a party I was hosting. I had done the same thing - made it public so that friends could join. In both cases, the people saw the event on a facebook feed of local events and saw that 10+ people were attending and thought it might be fun.

Both of those two people are now close friends of mine.

I share that just to say that I don't think it is odd to RSVP to a public event created by a friend even if you weren't formally invited. Heck, I would probably find it weird now, but back in college I didn't even find the strangers RSVPing to be all that odd.

I mean, I did make it public purposely so that people that weren't formally invited could attend. I just didn't expect someone from outside of that circle to want to attend.

This is the part I admit I don't understand. You were ok with people who weren't formally invited attending, but only SOME people who weren't formally invited, specifically people inside a specific circle. Except this was not communicated by creating a public event. A public event communicates: All are welcome, the more the merrier! It doesn't communicate: we only want people who know all of us to RSVP. And actually if you have a specific "circle", the best thing to do is invite them individually and make it a private event.